Portable sawing machine



Feb. 5, 1952 T. ST'ENINITT 2,584,821

PORTABLE SAWING MACHINE Filed April 5. 1948 in wni'ar:

Thomas 65672222 Patented Feb. 5, i952 2:,

"UNITED STATES PATENT OFFICE,

' Application April 3, 1948, Serial No. 18,796

In Canada June 12, 1947 V Y Claims. (01. 143-63) This invention relates to portable sawing machines.

An object of the invention is to provide a lightweight sawing machine which may be conveniently handled and operated by one man and which includes an improved and compact arrangement of parts whereby the machine is adapted for efficientoperation under varying conditions of use.

Other objects include the provision of an improved means for clamping the machine onto an element to be sawn whereby the machine is effectively and independently supported on the element, of an adjustable mounting means for a motor whereby the position of the latter may be maintained in proper operating position despite angular location of the machine, of adjustable loading means .for a saw to maintain eifective operation, and of improved clutch means for connecting the driving and driven shafts of the machine.

Various other objects, details and advantages of the invention will become apparent as the description proceeds with particular reference to the accompanying drawing, in which Figure 1 is a plan view of the sawing machine in accordance with the invention,

Figure 2 is a side elevation of the machine,

Figure 3 is a partial end elevation showing the motor mounting,

Figure 4 is an end elevation of the clutch and associated elements,

Figure 5 is a sectional side elevation of the saw carriage,

Figure 6 is a sectional end elevation of the saw carriage, and

Figure 7 is a side elevation showing a detail of the clamping means.

In the drawing, I is a substantially U-shaped frame member having arms 2, the ends of which are joined by a transverse member 3. Cross members 4, 5 and 6 extending between the arms 2 are provided for supporting various elements of the device. An upwardly and longitudinally extending member I constitutes a guard and carrying means for the machine, the forward end of such member 1 being fixed to a U-shaped guard and support member'B mounted on the forward ends of arms 2. r

A motor 9 is mounted on the forward end of the frame in offset relation to the longitudinal axis of the frame. The motor is carried by -a support. In having a base plate II, on which the motor rests, suspended from and between a pair of end plates 12. The plates l2 are adjustably mounted on the frame members 3 and 4 by means of rods I3 which extend through the members 3 and 4 and arcuate slots I4 and [5 in the plates. The inner ends of the rods are provided with heads l6 and the outer ends are pivoted to bellcrank levers I! having lugs l8 adapted to bear on member 3. The levers are pivotally connected to an arm 19, the end of which is connected by a link 20 to a lever 2| pivoted to a lug '22 on the frame. It will be observed that swinging of lever 2| outwardly will release the lugs l8 from bearing engagement with frame member 3 and thus permit the support to with motor 9 to be swung through the arc of the slots to adjust the level of the motor as desired should it be found necessary to operate the machine in a tilted position. The support l0 and motor 9 may be firmly locked in any desired position within the scope of their arcuate movement by swinging the lever 2! inwardly to the position shown in Figure 1, whereby the lugs F8 are clamped against frame member 3.

A pulley 23 is fixed to driveshaft 24 of the motor and is drivably connected to a stub shaft 25 journalled in bearings 26 on the frame, by a suitable clutch means 21. While various types of clutches may be employed, that shown is particularly well adapted for the purpose. A pulley 28, of considerably larger diameter than pulley 23, to provide desired speed reduction, is fixed to shaft 25 and a belt 29 normally loosely connects the .two pulleys topermit non-driving relation therebetween. Means for tightening the belt drivably to connect the pulleys comprises a roller 33 rotatably carried by an arm 3| pivoted to frame member 5, a second arm 32 pivoted to frame member 6, a spring 33 connecting the two arms, and a bellcrank lever 34 pivoted to a lug 35 on the frame and connected to arm 32 by a link 36. It will be observed that swinging of lever 34 in one direction will move the arm 3! and roller 39 into yieldable tightening engagement with the belt, as shown in Figure 4, while swinging of lever 34 in the opposite direction will release the roller 30 from belt-tightening engagement. A spring 31 connected to one end of lever 34 normally holds the lever in belt-tightening position. A clutch operating cable or wire 38, extending through a conduit 39,,is connected to the other end of lever 34 for manual actuation to disengage the clutch, i. 'e., move the lever 34 to non-belt-tightening:position.

Shaft 25 is drivably connected to a transverse driven shaft 40, journalled in bearings 4| on the frame, by means of a small gear 42 on shaft 25 and a large, crown gear 43 on shaft 40,, theratio of such gears being such as to provide a desired speed reduction. A guard 44 fixed to the frame may extend around the periphery of the gear 43.

One end of shaft 40 extends beyond the side of the frame and is provided with a small crank 45. A crank arm 46 is fixed to the outer end of shaft 40 and is pivotally connected to a pitman 41 which in turn is pivotally connected to carriage 48 reciprocally carried on a pair of transversely aligned tracks 49. The tracks are pivotally carried on the projecting end of shaft 46 by means of a sleeve 50 on the shaft and on which the ends of the tracks are fixed. The forward ends of the tracks are connected by a transverse member The carriage comprises a pair of side frame plates 52 on each of which is mounted a plurality of pairs of perpendicularly aligned rollers 53 having grooved peripheries for engagement therebetween of a respective track 49. The plates 52 are connected together by bolts 54 and 54'. A rapid, convenient and effective means for mounting or dismounting a drag saw 55 on the carriage comprises a U-shaped plate 56 carried at the forward end of the carriage by the bolt 54 and through which the end of the saw is adapted to extend, and a pin 51 having threaded engagement with a lug 58 fixed to the bolt 54 and the end of which is adapted to bear upon the edge of the saw rearwardly of the plate 56. The lower edge of the saw is preferably recessed at 59 for engagement with the lower bolt 54'. The pin 51 has a winged end 60 for ease of manual rotation. screwing of the pin downwardly will firmly clamp the edges of the saw between the web of plate 58 and bolt 54. The saw extends through a slot 6| in the'transverse member 51.

Means for manually swinging the tracks 49 and associated parts about their pivot comprises a forward upwardly extending arm 52 fixed to member 5|, a rearward upwardly extending. arm 63 fixed to sleeve 59, and a connecting handle 64. The handle 84 may also conveniently constitute a clutch actuating member. For this purpose, the handle may be rotatably mounted in the ends of arms 63 and 64 and be provided with a depending lug 65 to which the clutch actuating wire 38 is connected. Thus, manual rotative movement of the handle will exert a pull on the wire 38 to actuate the clutch.

When not in operation the free end of the tracks 44 may be supported on the frame by means of a lug 65 on the frame member 8 on which an opposed projection 61 on the arm 62 is adapted to rest.

An important feature of the invention resides in the provision of loading means for the saw to minimize the operators attention during the sawing operation and to facilitate and improve the latter operation. 'As is well known, in sawing devices of the present type, it is substantially essential for the operator to apply pressure manually to the sawing frame during the cutting operation to ensure satisfactory cutting and to eliminate harmful vibration. The present invention seeks to reduce or avoid this attention on the part of the operator by providing an adjustable saw loading device which comprises a segmental frame 68 fixed to sleeve 50. A lever 69 is pivoted at to sleeve 50 and has engagement with one or another of teeth H on the periphery of the segment. A spring 12 is connected at one end to the free end portion of lever 69 and at the other end'to the forward'main frame member 8. Itwill be apparentthat the spring,

acting through the lever and segment, will exert a downward swinging action on the tracks and associated parts about their pivot on the shaft, the force of such swinging action being adjustable by the setting of the lever in the toothed segment and/or by shifting the connection of the spring to the lever to one or other of the spaced points 13. Thus, a downwardly acting pressure will be exerted on the saw to maintain it in satisfactory cutting relation with respect to the work piece during the forward stroke and to eliminate vibration during the return stroke. The smallcrank 45 constitutes the usual means for permitting partial disengagement of the saw teeth with the work piece during the return stroke of the saw.

Means for clamping the device to a tree or the like for entire support therefrom comprises a pair'of downwardly and forwardly projecting spikes 14 fixed to the forward end of the main frame and a forwardly extending hook l5 pivotally mounted on the forward end of the main frame between the spikes 14 but closely adjacent the spike remote from the motor. Thus, the hook i5 is mounted on the lighter side of the machine, i. e., the side remote from that on which the motor is mounted. A spring "is normally holds the hook in rearwardly retracted position. In applying the device to a work piece, as indicated at 11, the spikes 14 are applied to the work piece, and, while manually supporting the machine, the hook i5 is pulled forwardly and its pointed extremity placed in engagement with the work piece as shown. 'Upon removing the manual support, the machine itself acts as a lever to drive the spikes and hook into the work piece and firmly to affix the machine to the latter for entire support therefrom, as will be apparent from Figure 2. The hook 15 is located on the lighter side of the machine to provide a more firm support for the machine when mounted on a tree or the like.

If the element to be sawn is a loose log or piece of wood lying on the ground, it is proposed to utilize the associated mechanism illustrated, wherein a lever 18, pivoted at '19 to the frame, has an adjustable connection with the hook 15 by means of a link pivoted to the lever and removably engaging a slotted member 8| on the hook. The link is provided with a series of notches 82 for engagement with one of a series of pins 83 extending transversely of the slotted member. A spring 84 connectedto the link holds the latter in engagement with an extension 85 on the lever 18 more positively to maintain the parts in any set position. In use, the rearward end of the machine is rested on the ground and the spikes 14 applied to the work piece H. The lever 18 is then pulled forwardly to depress the hook into firm engagement with the work piece.

The hook '15 may be extensible to accommodate various sizes of logs and the like. Thus, it may comprise two main parts 86 and 31, the hook-carrying part 86 having sliding engagement with the pivoted part 81. As shown part 86 has inturned edge portions 88- for overlapping engagement with'the complementary edge portions 89 of part 81. The parts are locked in any desired relation toeach other by means of, a lever 90 pivoted to part 86 and carrying a lug 9| engageable with one of a series of notches 92 in the edge of part 81. The lever is spring-pressed into engagement with a notch 92 by means of a spring '93 and is manually releasable from such engagement by depression of the thumb piece 94'. Means for automatically disengaging the clutch means 21 when a sawing operation is completed may be provided and, as shown, may comprise an L-shaped lever 95 pivoted to frame member 6 and having one arm connected by link 91% to clutch operating arm 32 and its other arm connected by means of a flexible adjustable connection 9? with a post 98 on the arm 93. The connection 97 may comprise a chain adapted to engage one of a series of notches 90 in the arm of lever 95. It will be apparent that when the tracks 49 reach a predetermined lower point at which a sawing operation is completed, it will exert a pull on chain 9! to actuate the lever 95 and move arm 32 to clutch-disengaged position.

While the dimensions of the machine may vary, it has been found that a machine as described may have a main frame not exceeding one foot in width and two feet in length. Moreover, the gross weight of the machine need not exceed thirty pounds. Thus, the machine is of particularly small size and light weight for ease of transportation and operation.

The machine described is particularly convenient and effective in operation, as will be apparent from the foregoing description.

A very important feature of the invention resides in the particular arrangement of saw, carriage and tracks in the manner described. It will be observed that the saw reciprocates in laterally opposed relation to and between the tracks 49, which thus constitute elongated guards for the saw during its reciprocal movement. This structure has been found to result in substantial elimination of buckling or pinching of the saw during sawing operations. major cause of trouble in the normal use of drag saws since frictional resistance between the saw and log or the like frequently results in buckling of the saw. To avoid such buckling, it has heretofore been necessary to drive a wedge into the cut in the log or to pry up the log in order to spread the cut and remove the frictional resistance between the saw and wood. Applicants structure removes the need for such inconvenient and time-consuming steps.

This application discloses certain subject matter disclosed and claimed in applicants copending application, Serial No. 702,725, filed October 11, 1946, now Patent No. 2,554,220.

What is claimed is:

1. In a sawing tool having a frame and a motor for actuating the tool, mounting means for the motor to permit upright positioning of the motor when the operating position of the frame is inclined, said mounting means comprising a motor supporting plate on which said motor is fixed, arcuate end plates fixed to the supporting plate on opposed edges thereof and havin aligned arcuate slots therein, rods carried by the frame and having sliding engagement with the walls of said slots, and means for locking said rods in any position within said slot.

2. A sawing tool as defined in claim 1, wherein said last-mentioned means comprises a pair of transversely aligned levers, each pivoted to the This is a 6 end of one of said rods, each said lever having a portion engageable with the frame to lock the rods against movement with respect to the frame, an arm connecting said levers, another lever pivotally mounted on the frame, and a link connecting said other lever and said arm, said other lever being swingable to release said lever portions from locking engagement with the frame.

3. A sawing tool comprising a frame, a shaft journalled therein, a sleeve rotatably mounted on the shaft, a pair of laterally aligned substantially parallel spaced rods having adjacent ends fixed to said sleeve and revolvable therewith, a saw-carrying carriage reciprocally mounted on the rods for longitudinal travelling movement thereon and comprising a pair of laterally aligned supporting plates, said rods being disposed between the plates, a plurality of pairs of rollers carried by each plate, each pair of rollers carried by each plate being aligned with and engaging therebetween a respective one of said rods, saw holding means carried by the carriage and located between said rods, a drag saw having one end fixed to the saw holding means and reciprocal therewith and between said rods, the side faces of said saw being in adjacent opposed relation to the opposed faces of said rods, said rods thus constituting tracks for said carriage and guards for said saw.

4. A sawing tool comprising a frame, a shaft journalled therein, a sleeve rotatably mounted on the shaft, a pair of laterally aligned substantially parallel spaced rods having adjacent ends fixed to the sleeve and revolvable therewith, a saw-carrying carriage reciprocally mounted on the rods for longitudinal travelling movement thereon and comprisin a pair of laterally aligned supporting plates, said rods being disposed between said plates, a plurality of pairs of rollers carried by each plate, each pair of rollers carried by each plate being aligned with and engaging therebetween a respective one of said rods, and saw holding means carried by the carriage and located between said rods, and power means mounted on the frame for imparting reciprocal motion through said shaft to the carriage.

5. A sawing tool as defined in claim 4, said saw holding means being arranged to clamp a saw in said carriage for disposition of the saw between said rods and comprising upper and lower bars each fixed to both said plates, an

inverted U-shaped member fixed to the upper bar in forward relation thereto and arranged to receive the saw between the legs thereof, a

lug fixed to the upper bar in rearward relation thereto and to the U-shaped member, and a pin having threaded engagement with the lug and arranged to engage the upper edge of the saw and clamp the latter between the web of said U-shaped member and said lower bar.

THOMAS STENNITT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 183,805 Holden Oct. 31, 1876 718,201 Gossett Jan. 13, 1903 925,194 Keough June 15, 1909 971,600 Freese Oct. 4, 1910 1,294,222 Bastian Feb. 11, 1919 1,364,054 Adams Dec. 28, 1920 1,524,790 Junke Feb. 3, 1925 1,734,212 Johnston Nov. 5, 1929 1,778,321 Hennig Oct. 14, 1930 2,413,485 Brown Dec. 31, 1946 

